The proposed research will examine the neural substrate of effector selection in the frontal eye fields (FEF) of awake and behaving monkeys. A goal-directed movement requires both localization of a target and the selection of an effector. The proposed research will examine how and where spatial information is integrated with information about the selection of an effector to produce a goal-directed movement. It has been assumed that, because FEF is involved directly in the production of saccadic eye movements, that FEF is an effector specific region. However, this assumption has not been systematically tested. In the proposed research we will determine if the responses of neurons in FEF are effector dependent under varying conditions. First, we will determine whether FEF is an area involved in the maintenance of information in working memory, or is an area involved in the maintenance of information for a goal-directed eye movement. Second, we will examine whether FEF represents a salience map for visual targets in general, or for the targets of eye movements, in particular. Third, we will determine whether FEF is involved in the process by which an effector is selected, in the absence of any spatial information regarding the target of an effector. Finally, will examine how and where spatial information is integrated with information about the selection of an effector in FEF and the lateral intraparietal sulcus (LIP).